Apparatus for crush dressing grinding wheels



2 Shets-Sheet l INVENTOR JOH N 0. WILSON ATTORNEY Jan. 24, 1950 J. c.WILSON APPARATUS FOR CRUSH DRESSING GRINDING WHEELS Filed Feb. 8, 1946FIG. I

Jan. 24, 1950 I J. c. w|| soN 2,495,492

APPARATUS FOR CRUSH DRESSING GRINDING WHEELS Filed Feb. 8, 1946 2Sheets-Sheet 2 FIG.5 26

Q v o a fii 66 FIG. 7

INVENTOIR Y JOHN 0. WILSON Patented Jan. 24, 1950 UNITED APPARATUS FGRCRUSH DRESSING. G-HINDIN G WHEELS- Appli'cwtilmzFebruary 8, 1946SeriaIiNcn. 6463ili4e 6' Claims. 1:

This invention relates to method and apparatus for. grinding, workpiecesand is especially concerned. with a method, and. apparatus for. grind.--ing, employing a. crushing. roll for. shaping, the. grinding. wheel.

In the present grinding of! workpieces. it. has been found that agrinding wheel". may be shaped to a very exact configurationby'employing a crushing roll as a dressing member. A crushing: rolliconsists; of a metallic roll; preferably hardenedv steel; which isforced" against; the wheel. while boththe roll; and. the wheel areoperating, at reduced. surface speed. The: effect of suchan. operationis to crush. the bonding which. holds. the particles of." grinding.material in the. wheel. and. thus to. transfer to. the. wheel'theconfiguration ofthe crushing, rolll.

Ina. dressing operation. of this type; it. is important that theperipheral speeds. of the wheel and roll be. identical in order to.produce the Best results.v Whilethisis automatically accomplished. whenthe. roll ofa simple. configuratibnit' is. not. true when. the roll has,relatively deep grooves therein.v In such. a roll; the. wheel and.rollwill. slip relatively, at some. poiht'along' their line oi? contactand. wearingofthe roll" will resul't'lwhich will reduce the. accuracyoi.the workpiece produced' on the machines The primary object of the.present. invention is to provide. animproved' method and" apparatus forcrush forming a grinding. wheel? wherein the configuration includesportions at substantially different radial distances: from the wheelaxis.v

Still another object is, to provide an improved which different partsof; the roll may rotate at,

different speeds in. order to" mai'ntainthe periph-, eral speedof theroll equal to the peripheral speed of the. wheel during. adressingcycle.

It is still; another object of the present. invention to provide a crushdressing roll. which is. divided into segments. by means of which. theshape. of'the rollimay he modified.

These. and. other. objects and. advantages. he come. more apparent upoILreference. to the. folilowing. specificationtaken together with theaccompanying drawings in which:

Figure L is an elevational view of a grinding machine adapted forpracticing the methods of this" invention;

FigureZ aside View of the machine of'Figure I showing. the. grinding:wheel: drive motor and. the slow speed motor which drives the grindingwheel during. the dressing cycle;

Figure 3 is; a view: showing; one type: of." over running? clutch;adapted. f 1rconnecting; the. slow SgEfifis motor with; the: spindlestrait;

Eigureiri isiasectionali view takem substantially; along; the: line:ie-41 offli'igure 1-.;;.

Figure 5,-

a: view talsem substantially alongthe line: 5.--5 of: Figure: and: showsthe grinding wheel. being: dressed; and! Figures: 6 and 7% are. wiewa.shnwring; different types; oti crushing. constituted. according: to:this: invention.

Refierringq tosthe; drawi gs I41 indicates thebedof;agrinder'onrwhichaisrnecipnocablyrmounteet a: table I12 te bedriven; by. a; motor; IL carried; in the said bed.

Connectedv with the; bedi. or" fixedly-r mounted adjacent thereto is a:eolumm tit that; supportsa saddle 1-8 for vertical. reciprocation bymeansz otthe nutv and screw arrangementsat 2.0,, the said; saddleint-urn, supporting; thewheelhead; stnuetune at..- 22. which isladaptedifor; reciprocation.

transversely in; the? saidsaddle.

Rotatable; within. the. wdieelhead 22;. by means of the shaft 24, is avg-ninding wheel 25 Theshaft 24, connected to; be: drivem air-grinding,speeds by a motor 28'; during. which time; the,- workpiece till. may he.recipnocatedl relative.- to. the. wheel. and have. ground; thereon the;confige uration. of the-wheel..

In. order. toformthe; veheefto; the. desiredishape, there. is. mounted.OII: the. table, l'2..a.rol1e1r generall yr indicated; at 32. whichpi'rotalIy mountedi in bracket. To. dressntheuwheelr 25,..the motor- 28.is, deenergi'zed'. to. bring the wheel. to. a halt and the table L2i'sthere'after: actuated; to. bring the roller; 32 directly. underthesaid wheel. The wheel; androlt are then hnoughtl together underpressure by feedingthawheel; downwardly by the nut and; screwarrangement: at; ThewheeL is drivenata reduced; speedtwhile heing. ur edv toward the roller. 31,. the. said". driving being ac.- compIi'shedrby. a. motor 36? which; drives; throughrediictibn. gearing, 311.amoizerrunning; clutch 4 L the shaft, it. Aftem-thez wheel; and; rollhave:heenfedltowardleachiother;atpred etermihed' amounii; the.- rotationof the; wheel halted the dressing operation is cprhplete; Ereferahl'y;the. feeding; together; of the: wlieel"v and". 110112 takes placeintermittently and the; lial'ting'of the; wheel afterdressing; takes.place; while the; said: wheel and roll; are; still" together;andilunderpressure;

The overrunning clutch. at fll i's:v indicated. at Figure: 3" and.vwill; be; seen tozcompfisee a sleeve memher- 42f a; member (Q1.rotatable: therein and; the: rollers; 41E whichzarez; adapted. to:drivingly' interconnect the memberse 4'2 and; H. in. one

direction of relative rotation and to permit free movement therebetweenin the other direction of relative rotation.

Referring to Figure 4, there is shown in section the workpiece 30 andthe wheel 26. It will be noted that the workpiece comprises a pair ofrecesses 48 and 59 which necessitates the upstanding ribs 52 and 56 onthe wheel 26. The wheel 26 is shown in Figure as being dressed by thecrushing roller 32 and it will be noted that the ribs 52 and 54 on thewheel lie in corresponding recesses in the roll 32. The actualperipheral speed of. the surfaces of the ribs 52 and 54 is considerablygreater than the speed of the surfaces indicated at 56 and 58.Accordingly, if the roll 32 were formed of one piece, as is usuallydone, there would be slipping between the wheel and the roll at eitherthe surface of the ribs or the surfaces 56 and -38 or both, the resultbeing considerable wear on the roll itself.

In order to overcome this difiiculty, this invention proposes toconstruct the roll 32 from a plurality of segments indicated at 60, 62,M, and 66 and to individually journal the said segments on thesupporting shaft 63 as by the bearings 10. The shaft 63 includes theflange 12 at one side thereof and a threaded portion which receives anut14 at the'other side thereof. The nut 14 is adapted for being located inposition by the set screw 76 so that the aforementioned plurality ofsegments may be closely held'together while being free to rotaterelatively. The shaft 68 is, in turn, journalled in the bracket 32' bythe bearings 78 at either end thereof.

By dividing the roll 32 into a plurality of segments, or discs, andpermitting the segments to rotate freely relatively, the peripheralspeed of the roller is maintained very near to that of the grindingwheel and a minimum of slippage therebetween takes place. Thissubstantially increases the life of the roller and maintainsgreateraccuracy in the workpieces produced in the grinding machine." v

Figure 6 illustrates an arrangement wherein there is a wheel 8ilhavingthe activeportions B2 and 84 to be dressed. For dressingtheseportions, there is provided a roll consisting of the segments or discs,8 6 and 88 which are separated by a spacer 9i) and'which areindividually journalled by the bearings 92 and 94 on the shaft 96. Thespacing collar as is of such a size that the segments 86 and 88 arespaced apart exactly the required distance. properly to form the activesurfaces on the wheel 80. Should it be desired or necessary to adjustthe spacing of the said segments, the collar 98 may be replaced by oneof a different size, or the collar Gil may include shims, the number ofwhich may be varied for adjusting the distance between the segments.Thus, in Figure 6 the segments are separately journalled for independentrotation in orderto maintain their peripheral speedequal, to that of thewheel while the collar 98 provides means for adjusting the exacttransverse spacing of the saidsegments and, therefore, of the active.surfaces on the,,wheel which is being dressed.

In Figure 7, there is a similar arrangement whereina wheel I03 has theedge portions I02 and H54 and a central portion I66 all of which are tobedressedto a predetermined configuration. The dressing roll inFigure '7consists of theend portions I es and i ii] and the centra'lpor tions H2all of which are individuallyjorirnalled onthe shaft 1 i4 and-closelybut loosely retained thereon between the collar I I6 and nut i 18. The

arrangement in Figure 7 is such that the exact configuration of thewheel I00 may be varied across its entire width by replacing thesegments H2, or by removing the said segments from the shaft H4 andmachining off a predetermined amount from the inside surface of one orboth thereof.

This invention then provides for a method of crushin a wheel havingrelatively deep grooves therearound while insuring a relatively longlife of the crushing roller. The method of this invention also insuresgreater accuracy of work- 0 pieces when the same are ground by agrinding wheel having grooves or upstanding ridges thereon by insuringthat the crushing roller employed for dressing the wheel will maintainits accuracy over a long period of time. This invention further providesa method for dressing a wheel by a crushing roll wherein .theconfiguration of the wheel may be modified without replacing the entireroll.

It will be understood that this invention is susceptible to modificationin order to adopt it to different usages and conditions and,accordingly, it is desired to comprehend such modifications within thisinvention as may fall within the scope of the appended claims.

I claim:

1. As a new article of manufacture, a multipart crushing roll for crushforming a grinding wheel to a predetermined contour comprising: aplurality of individual annular segments arranged side by side and eachadapted for dress ing a different annular part of the wheel to beformed, said segments taken as a unit having a contour complementary tothat to be formed on the wheel; and means supporting the said segmentsin rigid axial alignment and for free rotation relative to each other.

2. As a new article of. manufacture, a multipart crushing roll for crushforming a grinding wheel to a predetermined contour comprising: aplurality of individual annular segments arranged side by side and eachadapted for dressing a different annular part of the wheel to be formed,said segments taken as a unit having a contour complementary to that tobe formed on the wheel; means supporting the said segments in rigidaxial alignment and for free rotation relative to each other, and meansfor bringing said wheel and roll together for the simultaneousapplication of all of said segments to said wheel.

3. In a crush dressing device, a bracket; a shaft journalled in saidbracket and a multipart roll carried on said shaft in fixed axialposition relative to said shaft, said roll comprising a plurality ofannular, segments adjacently arranged, bearing means supporting each ofsaid segments on said shaft for individually free rotation relativethereto, said segments taken as a group being of substantially the sameaxial length as the part of the wheel to be dressed thereby forming acompound roller by which the wheel to be dressed can be formed by theapplication of said segments to the grinding wheel by a single movementof said wheel and roll relatively.

4. In a device for dressing a grinding wheel; a stationary bracket; ashaft carried by said bracket having a shoulder; a roll of substantiallythe same axial length as the part of the wheel to be dressed mounted onsaid shaft against said shoulder and a nut adjustable on said shaft forretaining said roll against said. shoulder, said roll being subdividedinto a plurality of parts along planes at right angles to the axis ofsaid shaft; means supporting each of said parts-on said shaft for freerotation relative thereto, each of said parts being adapted for dressingan individual annular part of said wheel.

5. In an apparatus for dressing a grinding wheel; a plurality of axiallyaligned cylindrical members and each adapted for dressing a differentaxial part of the periphery of a grinding wheel when pressedthereagainst; a shaft supporting said members for free individualrotation; and means retaining said members on. said shaft in apredetermined spaced relationship comprising collar means between saidmembers, a shoulder at one end of said shaft and adjustable abutmentmeans at the other end of said shaft; the said spaced relationship ofsaid members corresponding to the spacing on the wheel to be dressed ofthe parts of the wheel the members are to dress, whereby the wheel canbe completely dressed by said members in a single operation. V

6. The combination in a grinding machine for grinding workpieces havingalternate ribs and recesses; of a grinding wheel having alternate ribsand recesses extending annularly therearound and a dressing roll forshaping said wheel by pressure, said roll comprising a plurality ofindividual segments shaped to correspond to individual annular parts ofsaid wheel and some thereof being adapted for forming the said recessesin said wheel and other thereof being adapted for forming the said ribson said Wheel; a shaft supporting said segments for individual freerotation about a common axis; and means retaining said segments on saidshaft in rigid axial alignment with each other so that the configurationwhich they form as a unit is complementary to the form of the wheel tobe dressed, whereby the wheel can be fully dressed by said roll in asingle operation.

JOHN C. WILSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS 519,080 Great Britain Mar. 15, 1940

